U.S. patent application number 16/063511 was filed with the patent office on 2018-12-27 for method, apparatus and computer program product for accessing a local area scoped network having non-access-stratum procedures.
The applicant listed for this patent is Nokia Solutions and Networkds Oy. Invention is credited to Jari Pekka MUSTAJARVI, Mika Petri Olavi RINNE, Janne Petteri TERVONEN, Gyorgy Tamas WOLFNER.
Application Number | 20180376411 16/063511 |
Document ID | / |
Family ID | 55069841 |
Filed Date | 2018-12-27 |
United States Patent
Application |
20180376411 |
Kind Code |
A1 |
RINNE; Mika Petri Olavi ; et
al. |
December 27, 2018 |
Method, Apparatus and Computer Program Product for Accessing a
Local Area Scoped Network Having Non-Access-Stratum Procedures
Abstract
The present invention addresses a method, apparatus and computer
program product for accessing a local area scoped network having
non-access-stratum procedures, such as a MuLTEfire network, which
implement identifying an available access point of the local area
scoped network having non-access-stratum procedures, transmitting a
message to the access point, indicating a request for retrieving
network information, wherein the information are queried from the
network before authorization and actually connecting to the
network, selecting a service provider of the network based on
received network information for binding the network identity to
the selected service provider for accessing, and conveying a
Non-Access Stratum service request to the network to cause
authentication of the user equipment for connecting to the
network.
Inventors: |
RINNE; Mika Petri Olavi;
(Espoo, FI) ; WOLFNER; Gyorgy Tamas; (Budapest,
HU) ; MUSTAJARVI; Jari Pekka; (Espoo, FI) ;
TERVONEN; Janne Petteri; (Espoo, FI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nokia Solutions and Networkds Oy |
Espoo |
|
FI |
|
|
Family ID: |
55069841 |
Appl. No.: |
16/063511 |
Filed: |
December 19, 2016 |
PCT Filed: |
December 19, 2016 |
PCT NO: |
PCT/EP2016/081703 |
371 Date: |
June 18, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 74/0808 20130101;
H04W 76/27 20180201; H04W 12/0602 20190101; H04W 48/16 20130101;
H04W 48/17 20130101; H04L 5/0053 20130101; H04W 16/14 20130101;
H04W 48/18 20130101; H04W 48/14 20130101 |
International
Class: |
H04W 48/14 20060101
H04W048/14; H04W 76/27 20060101 H04W076/27; H04W 74/08 20060101
H04W074/08; H04W 12/06 20060101 H04W012/06; H04L 5/00 20060101
H04L005/00; H04W 48/18 20060101 H04W048/18; H04W 48/16 20060101
H04W048/16 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 18, 2015 |
EP |
PCT/EP2015/080560 |
Claims
1. A method comprising: identifying an available access point for
accessing a local area scoped network having non-access-stratum
procedures; transmitting a message to the access point, indicating
a request for retrieving network information, wherein the
information is queried from the network before authentication and
actually connecting to the network; selecting a service provider of
the network based on received network information for binding the
network identity of the selected service provider for accessing;
and conveying a Non-Access Stratum service request to the network
to cause authentication of the user equipment for connecting to the
network.
2. (canceled)
3. The method according to claim 1, wherein the network information
is exchanged with the network in at least one of Non-Access Stratum
signaling and Radio Resource Control messages.
4. The method according to claim 1, wherein the network information
comprises at least one of access information, information of at
least one service provider of the network, and network metrics.
5. The method according to claim 4, wherein the metrics comprise at
least one of a free channel airtime percentage, indicating a
relationship between a time when a channel has been detected to be
free and a time when channel has been detected to be occupied, over
a measurement period; a Physical Resource Block load, indicated by
a percentage of Physical Resource Blocks used per sub-frame
averaged over a large number of sub-frames; a Physical Resource
Block peak to average ratio, indicated by the ratio of the short
term peak number of Physical Resource Blocks occupied divided by
the long term average Physical Resource Block usage; an average
Packet Data Convergence Protocol Service Data Unit delay between
the access point and the user equipment; and a Channel Quality
Indicator load averaged over a specific time, indicative of the
interference load in the network.
6. The method according to claim 1, wherein no bearer establishment
is allowed while the user equipment is attached to the network in a
limited manner during the query procedure.
7. The method according to claim 1, wherein a temporary Cell Radio
Network Temporary Identifier is used for signaling the allocations
of radio resources.
8. An apparatus comprising: at least one processor, and at least
one memory for storing instructions to be executed by the
processor, wherein the at least one memory and the instructions are
configured to, with the at least one processor, cause the apparatus
at least to perform identifying an available access point of the
local area scoped network having non-access-stratum procedures;
transmitting a message to the access point, indicating a request
for retrieving network information, wherein the information is
queried from the network before authorization and actually
connecting to the network; selecting a service provider of the
network based on received network information for binding the
network identity to the selected service provider for accessing;
and conveying a Non-Access Stratum service request to the network
to cause authentication of the user equipment for connecting to the
network.
9. An apparatus including a function for enabling access of a user
equipment to a local area scoped network having non-access-stratum
procedures, comprising: at least one processor, and at least one
memory for storing instructions to be executed by the processor,
wherein the at least one memory and the instructions are configured
to, with the at least one processor, cause the apparatus at least
to perform receiving at a local area scoped network having
non-access-stratum procedures a message from the user equipment,
indicating a request for retrieving network information, wherein
the information is queried from the network before actually
connecting to the network; accepting the request without
authentication and transmitting network access information to the
user equipment; upon receiving information about a selection of a
service provider by the user equipment, binding the network
identity to the selected service provider for accessing; and upon
receiving a Non-Access Stratum service request from the user
equipment, allowing authentication of the user equipment for
connecting to the network.
10. The apparatus according to claim 8, wherein the network
information is exchanged with the network in at least one of
Non-Access Stratum signaling and Radio Resource Control
messages.
11. The apparatus according to claim 8, wherein the network
information comprises at least one of access information,
information of at least one service provider of the network, and
network metrics.
12. The apparatus according to claim 11, wherein the metrics
comprise at least one of a free channel airtime percentage,
indicating a relationship between a time when channel has been
detected to be free and a time when a channel has been detected to
be occupied, over a measurement period; a Physical Resource Block
load, indicated by a percentage of Physical Resource Blocks used
per sub-frame averaged over a large number of sub-frames; a
Physical Resource Block peak to average ratio, indicated by the
ratio of the short term peak number of Physical Resource Blocks
occupied divided by the long term average Physical Resource Block
usage; an average Packet Data Convergence Protocol Service Data
Unit delay between the access point and the user equipment; and a
Channel Quality Indicator load averaged over a specific time,
indicative of the interference load in the network.
13. The apparatus according to claim 8, wherein no bearer
establishment is allowed while the user equipment is attached to
the network in a limited manner during the query procedure.
14. The apparatus according to claim 8, wherein a temporary Cell
Radio Network Temporary Identifier is used for signaling the
allocations of radio resources.
15.-16. (canceled)
17. A method comprising: receiving, at a local area scoped network
having non-access-stratum procedures, a message from a user
equipment, the message indicating a request for retrieving network
information, wherein the information is queried from the network
before actually connecting to the network; accepting the request
without authentication and transmitting network access information
to the user equipment; upon receiving information about a selection
of a service provider by the user equipment, binding the network
identity to the selected service provider for accessing; and upon
receiving a Non-Access Stratum service request from the user
equipment, allowing authentication of the user equipment for
connecting to the network.
18. A non-transitory computer-readable medium comprising code
adapted to cause an apparatus to perform the steps of claim 1 in
response to execution of the code by the apparatus.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to wireless
communication networks, and more specifically relates to a method,
apparatus and computer program product for improved accessing a
local area scoped network having non-access-stratum procedures, in
particular a network according to the MuLTEfire technology.
BACKGROUND
[0002] Mobile data transmission and data services are constantly
making progress, wherein such services provide various
communication services, such as voice, video, packet data,
messaging, broadcast, etc. In recent years, Long Term Evolution
LTE.TM., and in particular LTE-Advanced.TM., has been specified,
which uses the Evolved Universal Terrestrial Radio Access Network
E-UTRAN as radio communication architecture according to 3GPP
specification.
[0003] Recently, a technology initiative called MuLTEfire (MF) has
been established. MF is communications system where LTE radio
technology is applied to unlicensed radio band. The difference to
the currently on-going Licensed Assisted Access (LAA/LTE-U)
activities is that in MF there is not expected to be macro network
nor licensed carriers in use, but instead MF is a standalone system
designed to operate on unlicensed band frequencies.
[0004] MF can operate e.g. on the same 5 GHz band as WLAN does.
Other unlicensed frequencies are available or may become available
at around 3.5 GHz, at 7 GHz, at 60 GHz and/or in several high
frequency bands above 6 GHz. Further unlicensed spectrum slices may
be appear in low frequencies below 1 GHz. MF technology is also
subject of the `MulteFire Alliance`.
[0005] However, for local area scoped network having
non-access-stratum procedures, in particular (but not restricted
to) MuLTEfire systems, there is the need for providing an improved
network selection.
[0006] As a related prior art in WLAN, a query protocol (Access
Network Query Protocol (ANQP) [IEEE802.11u]) was specified to allow
a device to retrieve information of available service Providers
from a WLAN network before authentication and before association.
This information obtained beforehand is crucial for the UE to
decide, which network to connect to. It is typical that in dense
area a large number of overlapping networks are available and a
large number of Access Points to connect to, can be found. It is
important to know beforehand, which Access Points belong to which
networks and which services each of the networks provide. ANQP is
e.g. in use for this purpose in the set of Hotspot (Passpoint)
protocols.
[0007] As another distant prior art, LTE networks can let UE
provide an emergency indication during initial attach request and
in that case a network may provide access to the limited emergency
services without authentication. However, in LTE environment in
general there is no need and hence there is no solution that
enables a UE to retrieve network access related information or
network service information before attaching/authenticating to
it.
SUMMARY OF THE INVENTION
[0008] Therefore, in order to overcome the drawbacks of the prior
art, it is an object underlying the present invention to provide
improved accessing a local area scoped network having
non-access-stratum procedures, in particular a network according to
the MuLTEfire technology.
[0009] In particular, it is an object of the present invention to
provide a method, apparatus and computer program product for
enhanced query of service providers in a MF network.
[0010] This object is achieved by a method, apparatus and computer
program product as defined in the accompanying claims.
[0011] According to a first aspect of the present invention, there
is provided method for a user equipment for accessing a local area
scoped network having non-access-stratum procedures, which may be
performed by a user equipment, comprising identifying an available
access point of the local area scoped network having
non-access-stratum procedures, transmitting a message to the access
point, indicating a request for retrieving network information,
wherein the information is queried from the network before
authentication/authorization and actually connecting to the
network, selecting a service provider of the network based on
received network information for binding the network identity to
the selected service provider for accessing, and further conveying
a Non-Access Stratum service request to the network to cause
authentication of the user equipment for connecting to the
network.
[0012] According to a second aspect of the present invention, there
is provided method for enabling access of a user equipment to a
local area scoped network having non-access-stratum procedures,
which may be performed in a network element of a MF network,
comprising receiving a message from the user equipment, indicating
a request for retrieving network information, wherein the
information is queried from the network before actually connecting
to the network, accepting the request without authentication and
transmitting network access information to the user equipment, upon
receiving information about a selection of a service provider by
the user equipment, binding the network identity to the selected
service provider for accessing, and upon receiving a Non-Access
Stratum service request from the user equipment, allowing
authentication of the user equipment for connecting to the
network.
[0013] According to a third aspect of the present invention, there
is provided an apparatus including a function for a user equipment
for accessing a local area scoped network having non-access-stratum
procedures, comprising at least one processor, and at least one
memory for storing instructions to be executed by the processor,
wherein the at least one memory and the instructions are configured
to, with the at least one processor, cause the apparatus at least
to perform identifying an available access point of the local area
scoped network having non-access-stratum procedures, transmitting
an associate request message to the access point, indicating a
request for retrieving network information, wherein the information
is queried from the network before authorization and actually
connecting to the network, selecting a service provider of the
network based on received network information for authorizing
binding the network identity to the selected service provider for
accessing, and further conveying a Non-Access Stratum service
request to the network to cause authentication of the user
equipment for connecting to the network.
[0014] According to a fourth aspect of the present invention, there
is provided an apparatus including a function for enabling access
of a user equipment to a local area scoped network having
non-access-stratum procedures, comprising at least one processor,
and at least one memory for storing instructions to be executed by
the processor, wherein the at least one memory and the instructions
are configured to, with the at least one processor, cause the
apparatus at least to perform receiving an associate request
message from the user equipment, indicating a request for
retrieving network information, wherein the information is queried
from the network before actually connecting to the network,
accepting the associate request without authentication and
transmitting network access information to the user equipment, upon
receiving information about a selection of a service provider by
the user equipment, binding the network identity to the selected
service provider for accessing, and upon receiving a Non-Access
Stratum service request from the user equipment, allowing
authentication of the user equipment for connecting to the
network.
[0015] According to a fifth aspect of the present invention, there
is provided a computer program product comprising
computer-executable components which, when the program is run, are
configured to carry out the method according to the first or the
second aspect.
[0016] Advantageous further developments or modifications of the
aforementioned exemplary aspects of the present invention are set
out in the dependent claims.
[0017] According to certain embodiments of the present invention,
the local area scoped network having non-access-stratum procedures
is a network according to the MuLTEfire technology.
[0018] According to certain embodiments of the present invention,
the network information comprise at least one of access
information, information of at least one service provider of the
network, and other information, such as network metrics, in a MF
network. That is, it is possible to query further information than
service provider information, such as the network metrics in a MF
network.
[0019] Further, according to certain embodiments of the invention,
the network information is exchanged with the network in at least
one of Non-Access Stratum signaling and Radio Resource Control
signaling messages.
[0020] Moreover, according to certain embodiments of the present
invention, the network metrics may comprise information about at
least one of capabilities and performance metrics of the
network
[0021] Thereby, according to certain embodiments of the present
invention, the metrics comprise at least one of a Physical Resource
Block load, indicated for example by a percentage of Physical
Resource Blocks used per sub-frame averaged over a large number of
sub-frames, a Physical Resource Block peak to average ratio,
indicated by the ratio of the short term peak number of Physical
Resource Blocks occupied divided by the long term average Physical
Resource Block usage, an average Packet Data Convergence Protocol
Service Data Unit delay between the access point and the user
equipment, and a Channel Quality Indicator load averaged over a
specific time, indicative of the interference load in the network.
Also, the used bandwidth allocations due carrier aggregation impact
on the percentage of PRB load i.e. if getting one component carrier
for allocations, the PRB load can be higher compared to allocating
on multiple component carriers. Bandwidth and/or carrier use
indication can be included to a load metric too.
[0022] Other load metrics due to unlicensed band operation can be
included, either together with the mentioned ones or without them.
Load can indicate free airtime percentage as free/busy time ratios
over a measurement period. Listen-Before-Talk procedures,
contention based access principles and collision probabilities have
an impact to these measures. As said, frequency use has a large
impact. There can be an opportunity for a frequency reuse 1
operation between MF-APs in the same network so that some MF-APs of
the same network can simultaneously operate on the same frequency
without mutual channel competition, while they compete for free
channels only relative to the other `alien` MF-APs or other
transmitters, like WLANs. Therefore, channel competition can impact
the other metrics like the PRB load. If MF transmitter does not get
the channel, the buffers will be filled with more data in the
meanwhile (queueing), which leads to a higher PRB load in the next
phase. Further, once competing for the channel per component
carrier, times with higher bandwidth allocation can serve high load
in shorter time compared to serving the load in smaller bandwidth.
This has an impact on the observed load metric, depending on its
preferred calculation.
[0023] According to certain embodiments of the present invention,
no bearer establishment is allowed while the user equipment is
associated (but not yet ATTACHED) to the network in a limited
manner during the query procedure.
[0024] Further, according to certain embodiments of the present
invention, a temporary Cell Radio Network Temporary Identifier
(C-RNTI) is used for signaling the allocations of radio resources
needed for the query procedure. The C-RNTI is validated into the
communication use after authentication and interface (bearer)
setup.
[0025] Still further, an example mechanism to identify the service
provider is binding the network identity to the Fully Qualified
Domain Name FQDN of the selected service provider for accessing,
wherein any format may be used as long as the participating
entities mutually understand it or are able compare and detect
matching identity.
BRIEF DESCRIPTION OF DRAWINGS
[0026] For a more complete understanding of example embodiments of
the present invention, reference is now made to the following
descriptions taken in connection with the accompanying drawings in
which:
[0027] FIG. 1 illustrates a method performed in a user equipment,
such as any 3GPP device category including smart phones, laptops,
wearables, communicators, pads, machines and internet of things,
according to certain embodiments of the invention;
[0028] FIG. 2 illustrates a method performed in a network element
of a local area scoped network having non-access-stratum
procedures, in particular a network according to the MuLTEfire MF
technology.
[0029] FIG. 3 depicts a general structure of an apparatus comprised
in a user equipment, including a function for accessing the user
equipment to a local area scoped network having non-access-stratum
procedures (e.g. MF network);
[0030] FIG. 4 depicts a block diagram of an apparatus comprised in
a network element, including a function for enabling access of a
user equipment to a local area scoped network having
non-access-stratum procedures (e.g. MF network);
[0031] FIG. 5 schematically shows a protocol stack according to
certain embodiments of the invention; and
[0032] FIG. 6 is an example of Non-Access Stratum NAS procedures
with query in a MF network.
[0033] FIGS. 7a and 7b schematically show state diagrams of a user
equipment in a MF network, wherein a combination of 3GPP states and
MF states are shown in FIG. 7a, and standalone MF states are shown
in FIG. 7b.
[0034] FIG. 8 shows an example of a NAS procedure for access to a
MF network comprising a query for identification of Participating
Service Providers (PSP).
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0035] Exemplary aspects of the present invention will be described
herein below. More specifically, exemplary aspects of the present
invention are described hereinafter with reference to particular
non-limiting examples and to what are presently considered to be
conceivable embodiments of the present invention. A person skilled
in the art will appreciate that the invention is by no means
limited to these examples, and may be more broadly applied.
[0036] It is to be noted that the following description of the
present invention and its embodiments mainly refer to
specifications being used as non-limiting examples for certain
exemplary network configurations and deployments. Namely, the
present invention and its embodiments are mainly described in
relation to 3GPP as well as MuLTEfire specifications being used as
non-limiting examples for certain exemplary network configurations
and deployments. As such, the description of exemplary embodiments
given herein specifically refers to terminology which is directly
related thereto. Such terminology is only used in the context of
the presented non-limiting examples, and does naturally not limit
the invention in any way. Rather, any other network configuration
or system deployment, etc. may also be utilized as long as
compliant with the features described herein.
[0037] Some example versions of the disclosure and embodiments are
described with reference to the drawings. In the following,
different exemplifying examples will be described using, as an
example of a communication network, a cellular wireless
communication network, such as an LTE or MuLTEfire based system.
However, it is to be noted that the present invention is not
limited to an application using such types of communication system,
but is also applicable in other types of communication systems, be
it wireless systems, wired systems or systems using a combination
thereof.
[0038] Hereinafter, various embodiments and implementations of the
present invention and its aspects or embodiments are described
using several alternatives. It is generally noted that, according
to certain needs and constraints, all of the described alternatives
may be provided alone or in any conceivable combination, also
including combinations of individual features of the various
alternatives. Also, the favorable execution order of features,
procedures may differ in different deployments or
implementations.
[0039] In particular, the following examples versions and
embodiments are to be understood only as illustrative examples.
Although the specification may refer to "an", "one", or "some"
example version(s) or embodiment(s) in several locations, this does
not necessarily mean that each such reference is to the same
example version(s) or embodiment(s), or that the feature only
applies to a single example version or embodiment. Single features
of different embodiments may also be combined to provide other
embodiments. Furthermore, words "comprising" and "including" should
be understood as not limiting the described embodiments to consist
of only those features that have been mentioned and such example
versions and embodiments may also contain also features,
structures, units, modules etc. that have not been specifically
mentioned.
[0040] In general, a wireless communication network comprises
plural network elements, such as evolved NodeB's (eNB; i.e. base
station in LTE/LTE-A environment), user equipments UE (e.g. mobile
phone, smart phone, Computer, etc.), controllers, interfaces, etc,
and in particular any equipment used in the provision of a
communications service.
[0041] The general functions and interconnections of the described
elements, which also depend on the actual network type, are known
to those skilled in the art and described in corresponding
specifications, so that a detailed description thereof is omitted
herein. However, it is to be noted that several additional network
elements and signaling links may be employed for a communication to
or from a base station and a communication network besides those
described in detail herein below.
[0042] As already indicated above, the present invention provides
an improved network selection for local area scoped network having
non-access-stratum procedures, in particular (but not restricted
to) MuLTEfire systems.
[0043] Currently, on the radio interface, MF relies on LTE
technology. While operation on unlicensed spectrum requires changes
to the LTE technology, the design goal is to have as few
modifications as possible. The LTE radio physical layer and related
protocols are being modified for the unlicensed spectrum operation
including Listen-Before-Talk (LBT) mechanisms for a fair channel
access between systems. The currently defined LTE unlicensed access
relies on control information and signaling exchanged on the
licensed carrier. The licensed carrier acts as Primary carrier or
Primary cell (PCell), whereas the unlicensed carrier acts as
Secondary Carrier or Secondary cell (Scell). MF is expected to
operate entirely on the unlicensed carriers. If MF has Primary and
Secondary carriers or Primary and Secondary Cells, they are all on
unlicensed spectrum. In MF, it is possible to change a Primary
carrier to another carrier, or the Secondary carrier to another
carrier or inter-change a Primary carrier to Secondary and vice
versa.
[0044] In the MF architecture, the radio interface terminates in
the UE and in the MF Access Point on the network side. For
simplicity, in the following the MF Access Point is also referred
to as MF-AP. As one alternative, MF-AP can be connected to a
conventional core network, i.e. Evolved Packet Core (EPC). In
another deployment alternative, MF-AP can be connected to a MF core
network (MF CN), which realizes the minimum set of necessary core
network functions for the MF operations, in a local network domain.
MF CN is intended to be as simple as possible, the target is to be
able to realize MF core network in one physical network equipment
(SW/HW). MF core network can be realized as a virtualized
implementation allowing cloud implementation. When MF network is
deployed with the MF core network, the network setup may resemble
WLAN deployment, however operating with 3GPP protocols. The MF CN
may be called mini-EPC, as an example.
[0045] As with any other communication system, MF networks need to
be identified uniquely in order the UE to select which network to
connect to and which service provider to select. This has
importance both in the initial network access and during mobility
procedures like handover with or without crossing network
boundaries. For example, 3GPP networks are identified with Public
Land Mobile Network (PLMN) identities that in practice identify the
(licensee) operator of the network. It is assumed that PLMN based
MF network selection is possible when MF is used as LTE extension
e.g. as unlicensed LTE nodes or as LTE subnets. However, MF is not
limited to the LTE mode only; it has also local service
provisioning, independent of PLMNs, here referred to as the local
MF mode. This way, MF provides an opportunity for access operators
and service providers (like Internet Service Providers, ISP), who
do not have cellular licenses and who do not operate PLMNs, neither
have registered/licensed PLMNI Ds.
[0046] A single MF network can be connected to multiple operators
having PLMNID or alternatively to Internet Service Providers. A
Service Provider in this context is any "operator" who can perform
the authentication (and charging) of a user to the network. This
has some similarity to how the Service Providers may use WLAN
access in hotspots. In a local area scoped network having
non-access-stratum (NAS) procedures, a user equipment UE should
learn the available Service Providers and should know whether the
preferred Service Provider is available before it attaches to the
network. The UE needs to indicate to the MF network which Service
Provider it would like to use for authentication. Service Provider
selection also defines used CN network and it is the CN which
initiates authentication.
[0047] The problem is that the number of Service Providers offering
connectivity from a single access network can be high and their
identities can be long. As said, the Service Providers of MF cannot
be expected to be cellular network operators having a PLMNID.
Rather, the Service Providers, in general, are identified by their
Fully Qualified Domain Names (FQDN). For these reasons, to
advertise the full identifiers of all the available Service
Providers in broadcast messages is not a feasible solution.
Advertising short format of the identifiers of the Service
Providers might be possible, but the short format of the
identifiers is not understandable for the end-users and hence
manual selection is not convenient enough. Assigning short formats
for FQDNs, the formats of which would be unique, may be
challenging. In particular, if automatically generating short
formats, their uniqueness may not easily be guaranteed.
[0048] In NAS access, the cellular network user identification used
for registration (customer info) is needed in addition to getting
the IP address for networking. These allow privacy, security and
charging as an example.
[0049] In the following description of embodiments of the
invention, the message indicating a request for retrieving network
information may, as a non-limiting example, also be referred to as
an `associate request` message. This exemplary terminology
expresses the purpose of e.g. associating a UE to a (MF-) network
for connecting to the network.
[0050] According to certain embodiments of the invention, signaling
procedures to access a MF network by the MF:NAS_Service_Request
message, according to the 3GPP Non-Access Stratum NAS protocols are
disclosed. The set of procedures include MF:NAS_Query, which can be
used to query information from the MF network before actually
connecting to the MF network and before executing the network
ATTACH. These procedures are needed to avoid the accessing UE to
attempt switching from the idle state to the connected state to a
MF network, where no suitable PLMN or Service Provider would be
available. Further the MF:NAS_Query is used by the UE to obtain
network metrics from the MF network before the ATTACH attempt, to
evaluate, whether the MF network is capable of well serving the UE
in terms of expected network load and offered quality.
[0051] The solution according to an aspect of the invention
basically comprises the following steps. At first, the UE sends a
MF:Associate_Request with a new request type, which indicates that
UE retrieves access information (e.g. names of available access
network providers or Service Providers), before the actual
MF:NAS_Service_Request will be executed. Then, the network may
accept the MF:Associate_Request without authentication for
exchanging a limited and defined set of network Query Information
elements. The information can be exchanged un-ciphered. The network
in this phase allows the UE to send only a limited set of special
type of messages or Information elements in a message for the
Query, and the network hence delivers the requested information.
The requested information provided by the network may be an exact
response to the query of the UE, or the network may append the
information to a suitable length. The network may also include
optional information elements to its query response. After
receiving sufficient information, the UE may decide to attempt
network access and will transmit the actual MF:NAS_Service_Request
in the NAS message, which also terminates the Query. The NAS
termination point in the network (MME similar to the legacy LTE
networks, mini-EPC in MF, or MF CN) can send replies to these
requests in the NAS messages or initiate other dedicated signaling
with the UE.
[0052] Thereby, the UE and the network should terminate the session
after a short time of query. No bearer ("eps-bearer") establishment
is allowed while the UE is associated (but not yet ATTACHED) to the
network in this limited manner. After the MF:NAS_Service_Request is
served by the network and after the authentication is successful,
the UE changes to the ATTACHED state.
[0053] The NAS service request can include an identity of a UE or a
user in terms given by the Service Provider. Such identity can have
a form of a bit field, a uniform resource name (urn), a temporary
subscriber identity, any service provider given user identity, e.g.
a number, or an identity that is valid in a given MF network.
[0054] FIG. 1 illustrates a method for accessing a user equipment
to a local area scoped network having non-access-stratum procedures
(e.g. MF network) performed in a user equipment according to
certain embodiments of the invention.
[0055] In Step S11, an available access point of the local area
scoped network having non-access-stratum procedures is
identified.
[0056] In Step S12, a message, such as e.g. an associate request
message MF:Associate_Request, is transmitted to the access point,
indicating a request for retrieving network information (e.g.
comprising at least one of information of at least one service
provider of the network, network metrics and any access
information), wherein the information is queried from the network
before authenticating and actually connecting to the network.
[0057] Further, in Step S13, a service provider of the network is
selected based on received network information for binding the
network identity to (e.g. the Fully Qualified Domain Name) the
selected service provider for accessing.
[0058] Then, in Step 14, a Non-Access Stratum service request
MF:NAS_Service_Request is conveyed to the network to cause
authentication of the user equipment for connecting to the
network.
[0059] FIG. 2 illustrates a method for enabling access of a user
equipment to a local area scoped network having non-access-stratum
procedures (e.g. MF network) performed in a network element (e.g.
of a MF network) according to certain embodiments of the
invention.
[0060] In Step S21, a message, such as an associate request message
MF:Associate_Request, is received from the user equipment,
indicating a request for retrieving network information,
information (e.g. comprising at least one of information of at
least one service provider of the network, network metrics and any
access information), wherein the information is queried from the
network before actually connecting to the network.
[0061] In Step S22, the (associate) request is accepted without
authentication and transmitting network access information to the
user equipment.
[0062] Further, in Step S23, upon receiving information about a
selection of a service provider by the user equipment, the network
identity is bound to the (e.g. Fully Qualified Domain Name of) the
selected service provider for accessing.
[0063] Then, in Step 24, upon receiving a Non-Access Stratum
service request, MF:NAS_Service_Request from the user equipment,
authentication of the user equipment for connecting to the network
is allowed.
[0064] In FIG. 3, a diagram illustrating a configuration of an
element comprised in a user equipment implementing a function for
accessing a user equipment to a local area scoped network having
non-access-stratum procedures (e.g. MF network) according to some
example versions of the disclosure is shown. The embodiment may be
carried out in or by the user equipment. It is to be noted that the
user equipment may comprise elements or functions, such as a
chipset, a chip, a module etc., which can also be part of the user
equipment or attached as a separate element to the user equipment,
or the like. It should be understood that each block and any
combination thereof may be implemented by various means or their
combinations, such as hardware, software, firmware, one or more
processors and/or circuitry.
[0065] The apparatus 3 shown in FIG. 3 may comprise a processing
function, control unit or processor 31 such as a CPU or the like,
which is suitable for executing instructions given by programs or
the like related to the network element control procedure.
[0066] The processor 31 is configured to execute processing related
to the above described access to a local area scoped network having
non-access-stratum procedures (e.g. MF network). In particular, the
processor 31 comprises a sub-portion 310 as an identification unit
configured to identify an available access point of the local area
scoped network having non-access-stratum procedures. The portion
310 may be configured to perform processing according to S11 of
FIG. 1. Furthermore, the processor 31 comprises a sub-portion 310
usable as a transmission unit configured to transmit a message to
the access point, indicating a request for retrieving network
information, wherein the information is queried from the network
before authentication and actually connecting to the network. The
portion 311 may be configured to perform processing according to
S12 of FIG. 1. Still further, the processor 31 comprises a
sub-portion 312 usable as a selection unit configured to select a
service provider of the network based on received network
information for binding the network identity to the selected
service provider for accessing. The portion 312 may be configured
to perform processing according to S13 of FIG. 1. Moreover, the
processor 31 comprises a sub-portion 313 usable as a processing
unit configured to conveying a Non-Access Stratum service request
to the network to cause authentication of the user equipment for
connecting to the network. The portion 313 may be configured to
perform processing according to S14 of FIG. 1.
[0067] FIG. 4 depicts a block diagram of an apparatus comprised in
a network element, including a function for enabling access of a
user equipment to a local area scoped network having
non-access-stratum procedures (e.g. MF network). It should be
understood that each block and any combination thereof may be
implemented by various means or their combinations, such as
hardware, software, firmware, one or more processors and/or
circuitry.
[0068] The network element 4 shown in FIG. 4 may comprise a
processing function, control unit or processor 41 such as a CPU or
the like, which is suitable for executing instructions given by
programs or the like related to the network element control
procedure.
[0069] The processor 41 is configured to execute processing related
to the above described access to a local area scoped network having
non-access-stratum procedures (e.g. MF network). In particular, the
processor 41 comprises a sub-portion 410 as a reception unit
configured to receive a message from the user equipment, indicating
a request for retrieving network information, wherein the
information is queried from the network before actually connecting
to the network. The portion 410 may be configured to perform
processing according to S21 of FIG. 2. Furthermore, the processor
41 comprises a sub-portion 411 usable as an accepting unit
configured to accepting the request without authentication and
transmitting network access information to the user equipment. The
portion 411 may be configured to perform processing according to
S22 of FIG. 2. The portion 410 may be configured to perform
processing according to S21 of FIG. 2. Furthermore, the processor
41 comprises a sub-portion 412 usable as binding unit configured to
bind, upon receiving information about a selection of a service
provider by the user equipment, the network identity to the
selected service provider for accessing. The portion 412 may be
configured to perform processing according to S23 of FIG. 2. Still
further, the processor 41 comprises a sub-portion 413 usable as
processing unit configured to, upon receiving a Non-Access Stratum
service request from the user equipment, allow authentication of
the user equipment for connecting to the network. The portion 413
may be configured to perform processing according to S24 of FIG.
2.
[0070] In FIGS. 3 and 4, reference signs 32, 42 and 33, 43 denote
transceiver or input/output (I/O) units (interfaces) connected to
the processor 31, 41. The I/O units 32, 42 may be used for
communication with the elements. The I/O units 33, 43 may be used
for communicating with a management application. Reference sign 34,
44 denotes a memory usable, for example, for storing data and
programs to be executed by the processor 31, 41 and/or as a working
storage of the processor 31, 41.
[0071] FIG. 5 schematically shows a protocol stack according to
certain embodiments of the invention. An UE 51 is connected to a MF
network element 53 via a MF-AP 52. The UE 51 comprises layers, such
as radio layers, Radio Resource Control RRC and Non-Access Stratum
NAS, whereas the MF network element 53 comprises transport layers
and Non-Access Stratum NAS.
[0072] The new messages are transferred between the UE and MF
Network Element in NAS signaling. They are transparent to MF-AP 52,
and it is possible to apply encryption to provide some level of
security (e.g. privacy). Note that this does not mean that the UE
51 and the network authenticate each-other yet.
[0073] FIG. 6 is an example of Non-Access Stratum NAS procedures
with query in a MF network. The phases include 1) network
identification, 2) query, 3) service request, 4) interface setup
and 5) mobility.
[0074] The network identification includes a network-type equal to
MF and network identity, which has a defined relationship to the
service provider. The relationship of MF identity to the service
provider identity may be a HASH function, or MF identity can be a
given identity for a given service provider (e.g. assigned by some
organization).
[0075] NAS associate request, MF:NAS_Associate_Request, may be
quite a minimized procedure as follows; after the UE has selected a
MF-AP based on signal measurements and based on its advertised MF
identity to communicate with, the MF-AP uses a temporary-cRNTI
(Cell Radio Network Temporary Identifier) for signaling the
allocations of radio resources for the query phase. The actual
c-RNTI can later be assigned for use during and after the radio
bearer setup. As a novelty, c-RNTI can identify the UE operational
in a MF network, despite of whether the UE's full identity is
granted by the cellular operator or by a service provider.
[0076] The query phase includes binding of the MF network identity
to the service provider. The MF network identity can indicate the
access network provider, which can be the same as the Service
Provider or it can be different from the Service Provider. A single
access provider can provide access network for multiple Service
providers. After the service provider is selected accordingly, UE
may move in the MF network by selecting cells, which have the
correct MF identity and omitting cells, whose MF identity does not
match. In this selection, further query is not needed, because the
MF network identity is sufficient to ensure the initially queried
information is valid and the same Service Provider is reachable.
This binding covers at least all the following; the access network
provider is the same as the Service Provider, the access network
provider is different from the Service Provider, the access network
provider provides multiple, a list of, Service Providers.
[0077] In addition to finding the service provider, UE may find
further information about at least one of the capabilities and
performance metrics of the MF network or a network segment. This
way, the UE may already in an early phase, before authentication,
decide whether it will try to access this MF network or not.
[0078] In FIG. 6, the interface setup. MF:Interface_Setup is
actually a procedure which will create the necessary logical
interfaces in the MF network, and it will result in radio bearer
setup between the MF-AP and the UE, and it will hence create the
interface between the UE and the network. The "interface" between
the UE and the MF network can be an IP address.
[0079] Hence the process illustrated in FIG. 6 may actually consist
of more than one elementary procedures. It is noteworthy that the
"interface" in FIG. 6 is not drawn to the UE even if it actually
creates the interface for a UE in the network. That is what happens
according to the invention in the radio bearer setup i.e. the NAS
level interface is established on top of establishing the radio
bearer. The "interface" is a logical higher layer interface, which
may be an IP address, a network interface identifier, an access
service set identifier or it may be a conception of a bearer,
similar to eps-bearer, for example. In an embodiment according to
what is described above, a bearer may not need to exist if the
interface is functional by some other logical relationship between
the network elements.
[0080] After the interface setup as well as the bearer setup,
mobility in the MF network is provided by a forward type of
handover, but as well a backward type of handover could be provided
at least for a robust backup solution. Further, re-establishment
procedures to a new target cell can be executed, because context
fetch from any source cell can be expected to be fast and executed
easily inside a MF network domain.
[0081] In another embodiment of the invention, the query procedure
may be executed as a set of Radio Resource Control (RRC) messages,
instead of, or in addition to the NAS-messages. NAS-message, in
here, is any message which is exchanged between the UE and the core
network entity (MF CN) with or without MF-AP involvement.
RRC-procedure can be used for fetching information available in the
MF-AP, such as the metric information. It is possible that some
metric information has to be fetched from a more distant network
element for example from the mini-EPC or from a server. Service
Provider information would require fetching from the MF CN.
NAS-procedures can be operational between the UE and the MF CN,
hence the procedure called MF:NAS_Query can mean a procedure, which
executes for the NAS access, either in the RRC-procedure, in the
NAS-procedure or in combination thereof. So, the said MF:NAS_Query
is a procedure operating for the NAS, despite of the actual
procedural layers it is implemented into.
[0082] Generally, NAS access is the concept of the set of
non-access stratum signaling procedures, i.e. the means how UE
connects to and ATTACH to the core network element in the MF
network. NAS access is clearly different from WLAN, which is not a
cellular network but rather WLAN is an extension of the Ethernet.
WLAN works with its permanent device Ethernet MAC-address and acts
as the first/last few tens of meters of the Ethernet. NAS
concretely defines that MF is a 3GPP compatible network in its
procedures.
[0083] In MF NAS network, the UE identification can be linked to
the PLMN's registry as the home subscription (or to a visited
subscription) or to a service provider registry such as to a
uniform resource name (urn). Such urn could be obtained e.g. by a
registration into a web-page.
[0084] As described herein, according to the invention, the
MF:NAS_Query procedure can be used to retrieve network metrics from
the LTE based unlicensed MF network. Some example metrics are given
below.
[0085] --PRB Load:
[0086] Percentage of Physical Resource Blocks (PRB) used per
sub-frame averaged over a large number of sub-frames. For example,
PRB load 5% vs PRB load 60% could show a clear difference in the MF
network loading in terms of its average resource usage. This metric
can be queried per cell or per MF network. When the metric is
queried per MF network, the metric is returned as averaged over all
the cells of the MF network (or a subnet). There may be notable
differences in load in different cells in the MF area.
[0087] --PRB Peak to Average Ratio:
[0088] The ratio of the short term peak number of PRBs occupied
divided by the long term average PRB usage. For example, this ratio
could be 20% or 500%, which could show that the PRB resource use is
very peaky. For example for the 20% average PRB load the peak of
20% could consume 24% of PRBs whereas the peak of 500% could
consume 100% of PRBs respectively. The time unit for the peak
calculation can be set to a value from a single sub-frame to a
defined number of sub-frames smaller than the averaging period.
[0089] --Delay:
[0090] Average Packet Data Convergence Protocol (PDCP) Service Data
Unit (SDU) delay (round-trip-time) between the MF-AP and the UE or
between the gateway and the UE depending on the definition. This
metric can be averaged over the (population) of served UE and
differentiated per QoS class i.e. the delay can be given per QoS
Class Identifier (QCI). Note, the PDCP SDU can typically be for
example an IP packet. An IP packet could for example carry a
Transmission Control Protocol (TCP) segment or a unit of the User
Datagram Protocol (UDP).
[0091] --CQI Load:
[0092] Channel Quality Indicator (CQI) metric can be averaged over
a long time. CQI is a measure of signal to interference ratio.
MF-AP knows this from its served UE's reports, and it is indicative
of the interference load in the cell or in the MF network. This
metric can be queried per cell or per MF network (or a subnet).
When the metric is queried per MF network, the metric is returned
as averaged over several UE reports (of link quality) in all the
cells of the MF network. There may still be notable differences in
CQI loading in different cells in the MF area. Also, the UEs in a
single cell may report largely different CQI load due to their
location in the cell area. It is also possible that the UE
observations are very heterogeneous i.e. the UE reported CQIs are
observed from some locations (dense) more than from other locations
(spare). The eNB can include to a CQI load metric a set or a subset
of CQI observations from a set or a subset of UEs, the observations
of which it considers relevant for the metric.
[0093] FIG. 7 shows the state diagrams of a UE in a MF network. MF
network states can appear as concurrent to the 3GPP state(s) or the
states can be standalone (without other 3GPP networks). The
compound 3GPP states and MF states are shown in FIG. 7a, and the
standalone MF states are shown in FIG. 7b.
[0094] In both cases, the UE state in a MF network is independent
of its state(s) in the 3GPP networks. Hence, any state in the 3GPP
network may lead to the MF connected state. Reference sign 71 in
FIG. 7a shows the UE in E-UTRA (LTE) RRC Connected state making a
MF Query and possibly entering to the MF connected state. Reference
sign 72 shows the MF state transition while UE being in the E-UTRA
(LTE) RRC Idle state.
[0095] In the MF, despite of the state in the 3GPP network, the
associate is done first without a state transition. While
associated, the UE may make Query according to the embodiments of
the invention, whether to get connected to a MF network or not. If
the UE decides, based on the Query, not to attempt connection to a
MF network, the UE will remain in the original state, from where it
can make an association to another candidate MF network and execute
Query for that. If UE in any of these associations get favorable
Query response, the UE can decide to attempt connecting to the
selected MF network. In case the following NAS-procedure is
successful, the UE can reach connected state in the selected MF
network. It is also possible that the NAS procedure will lead to a
failure e.g. due to authentication error despite of UE selecting a
feasible Service Provider, which will cause the UE not to reach the
MF connected state but return to the original state. Once if
reaching the MF connected state, it is possible that later the UE
from its own initiative or from the MF network initiative will be
released from the MF network. This is shown by reference sign 73 in
FIG. 7a.
[0096] The Query phase is shown in FIG. 7a as a pass-through box,
which indicates that the Query does not form a UE state of its own
but is rather an intermediate functionality, for information Query
according to the invention, which lets the UE decide to terminate
the Query either to the original state or to the NAS service
request attempt towards the MF connected state, ending to the MF
connected state or to a failure return to the original state.
However, yet an alternative embodiment can be envisioned, where a
Query happens in a clearly defined state of its own.
[0097] In FIG. 7b, an UE is shown with the standalone MF states.
The operation is similar to FIG. 7a in respect to the MF network
without any concurrent aspect of the 3GPP network. Hence UE in idle
state may decide to associate to a MF-AP and do Query according to
the invention. If the UE decides, based on the Query, not to
attempt connection to a MF network, the UE will remain in the
original state, from where it can make an association to another
candidate MF network and execute Query for that. If UE in any of
these associations get favorable Query response, the UE can decide
to attempt connecting to the selected MF network. In case the
following NAS-procedure is successful, the UE can reach connected
state in the selected MF network. It is also possible that the NAS
procedure will lead to a failure e.g. due to authentication error
despite of UE selecting a feasible Service Provider, which will
cause the UE not to reach the MF connected state but return to the
original state. Once if reaching the MF connected state, it is
possible that later the UE from its own initiative or from the MF
network initiative will be released from the MF network. This is
shown by reference sign 74 in FIG. 7b.
[0098] Again, the Query phase is shown in FIG. 7 as a pass-through
box, which indicates that the Query does not form a UE state of its
own but is rather an intermediate functionality, for information
Query according to the invention, which lets the UE decide to
terminate the Query either to the original state or to the NAS
service request attempt towards the MF connected state, ending to
the MF connected state or to a failure return to the original
state. However, yet an alternative embodiment can be envisioned,
where a Query happens in a clearly defined state of its own.
[0099] A special use case of a NAS procedure as illustrated in FIG.
6 is the access procedure to a MF network with service provider
query. A MF radio access network (MF-RAN) may be connected to the
core network of a mobile network operator (MNO), such as the 3GPP
evolved packet core network (EPC), and may therefore provide
basically conventional access to a mobile network, often referred
to as PLMN access mode in MF. Alternatively or additionally, the
MF-RAN may be operated in a mode, often referred to as neutral host
network (NHN) in MF, supporting access to multiple participating
service providers (PSP). A UE accessing a NHN shall be able to
retrieve information about the service providers, which offer
authentication and connectivity via the MF network. One MF network
may support multiple PSPs, from which the UE may select a preferred
PSP during initial access to the network.
[0100] System information (SI) provided in a MF cell may include a
list of available PSPs, which may be identified by their names,
similar to domain names, to a user. These full names may typically
be too long for costly transmission in SI, since SI resources are
scarce in a cell and information elements of the SI need to be
transmitted periodically with full-coverage power. Further,
operation in unlicensed spectrum may require the execution of a
listen-before-talk (LBT) procedure before each transmission burst
related to SI. Therefore, one may consider broadcasting of short
PSP-IDs in SI instead of the full PSP names, and one may further
consider to broadcast in SI only information related to a subset of
the available PSPs, for example the most requested PSPs in a cell
or network area. Therefore, an additional mechanism is needed which
allows a UE in a cell to retrieve thorough information of PSPs
associated with PSP-IDs broadcast in SI, for example, a list of
unique identifiers such as full names of PSPs available in the
cell. This mechanism may provide a list comprising full names, of
arbitrary length for an arbitrary number of PSPs. The list may be
provided in a message or information element with predetermined or
preconfigured maximum length.
[0101] The full names or unique identifiers of the PSPs may be
provided in a NAS procedure comprising a respective query. The NAS
procedure may be executed based on certain enhancements of
signaling procedures specified in LTE for use in a LTE-based MF
network providing access to non-MNO service providers in unlicensed
spectrum. The steps of the NAS procedure related to the service
provider query may be executed in an LTE-based MF network for a UE
entering RRC connected state without triggering or requesting the
NAS attach procedure in LTE, i.e. without triggering EPS bearer
setup and/or setup of interfaces for user data transmission.
[0102] FIG. 8 shows a signaling diagram of a procedure comprising a
NAS service provider query in a LTE-based MF network. A UE may
trigger the NAS service provider query when information on
available PSPs in a cell is not sufficient for the UE. The SI in
the cell may, for example, not include information on PSPs, or may
only include a subset of the available PSPs or may only include
short PSP-IDs when the UE needs unique identifiers of the PSPs,
such as full names. The UE may also trigger the NAS service
provider query when it refrains, for some reason, from reading
PSP-related information in the SI.
[0103] Steps related to the network identification and MF-AP
selection, as shown in FIG. 6, have been omitted in FIG. 8. The
"MF: Associate Request" in FIG. 6 may comprise a random access
attempt to a MF cell meeting the cell selection criterion. For
example, in an LTE-based network the random access procedure may
comprise the transmission of a first message (Msg1) in step 810
from the UE on a physical random access channel (PRACH) suitable
for operation in unlicensed spectrum. Specifically, the UE may
transmit a random access preamble on PRACH in step 810 after
reading the cell's random access configuration from SI.
[0104] In step 820, the MF-AP may detect the random access preamble
sent through the PRACH. The MF-AP may then send a second message
(Msg2) known as random access response (RAR) to the UE. The RAR may
in particular comprise a scheduling grant, indicating initial
resources for UL transmission in the next step of the procedure and
a temporary C-RNTI (cell radio-network temporary identifier). The
UE may determine the RAR destined to it based on the RA-RNTI
(random access radio network temporary identifier) used on a
scheduling control channel, such as the PDCCH (physical downlink
control channel) in an LTE-based network. The RA-RNTI in turn may
be associated with the PRACH resources used for transmission of the
random access preamble in step 810.
[0105] Using the initial resources the UE may send a third message
(Msg3) in step 830 comprising control information indicating a
request for a query related to a MF network, for example a service
provider query in a MF cell. The message may be provided using a
preconfigured or predetermined bearer and channel configuration.
For example, in an LTE-based network the message may be provided
using signaling radio bearer 0 (SRB0) on the Common Control Channel
(CCCH). The radio link control (RLC) layer in such a network may be
configured for data transmission in transparent mode (TM). In an
embodiment the UE may use a message similar to the
RRCConnectionRequest message in LTE including a cause information,
for example "required PSP", for indicating a respective query
request to the network. The requesting UE may be identified to the
MF network through a UE-ID set to a random value, since the UE has
not yet selected a PSP, so that the UE does not know which
registered UE-ID it should use.
[0106] In step 840 the MF-AP may use said preconfigured or
predetermined bearer and channel configuration and respond to the
message received in step 830. The message in step 840 may comprise
a first specific bearer and channel configuration, similar to SRB1
in LTE, for further transmission of control information on the
Dedicated Control Channel (DDCH). The first specific bearer and
channel configuration may be used for transmission of control
information related to the access stratum (AS), i.e. the protocols
and parts of the network being specific to the access technique.
The first specific bearer and channel configuration may further be
used for transmission of control information related to the
non-access stratum (NAS), i.e. protocols between a UE and the core
network which are not terminated in the RAN, until a second
specific bearer and channel configuration, similar to SRB2 in LTE,
for control information related to the NAS has been established.
The temporary C-RNTI may become the C-RNTI after detection of the
message in step 840 at the UE, and may be used at the physical
interface to identify data transmissions to the UE. Higher layers
may still use the UE-ID set to a random value from step 830 for
identifying the UE to the MF network. In an embodiment the MF-AP
may use in step 840 a message similar to the RRCConnectionSetup
message in LTE.
[0107] In step 850 the UE may respond to the message received in
step 840. The message in step 850 triggers a NAS query related to
the MF network. The NAS query request and the type of the query may
be indicated through a respective information element "NAS Query"
in the message of step 850, or may be derived from the cause
information transmitted in step 830. Alternatively, an information
element "NAS Query" may only indicate the query request as such,
and the MF network may derive the type of the query, for example a
PSP query request, from the cause information transmitted in step
830. The message in step 850 may be transmitted using the first
specific bearer and channel configuration. The message in step 850
may further include information needed for establishing the second
specific bearer and channel configuration for transmission of
control information related to the NAS. In an embodiment the UE may
use in step 850 a message similar to the RRCConnectioSetupComplete
message in LTE. However, the message in step 850 may not contain an
attach request, unlike the conventional RRCConnectionSetupComplete
message in LTE, and will therefore not cause establishment of a
transport mechanism for user data between the UE and the MF-CN. In
other words, the message in step 850 may not connect the UE to the
MF-CN by a user data transport mechanism similar to the EPS bearer
in LTE, which specifies the route and certain quality of service
parameters for the transmission of user data between the UE and the
MF-CN. The message in step 850 may, therefore, not cause
configuration of respective interfaces, for example interfaces
similar to the S1 u-plane in LTE, for user data transmission. The
message may further not cause authentication of the UE and the
MF-CN to each other.
[0108] In step 855 the MF-AP may provide information related to the
NAS query in the message of step 850 to the MF-CN.
[0109] In step 860 the MF-CN may respond to the NAS query. The
second specific bearer and channel configuration may be used for
transmitting the response to the NAS query. The same random UE-ID
may be used in the NAS query and in the response to the NAS query
for identifying the requesting UE. The response may be transmitted
in a NAS message comprising an identifier indicative of the
included NAS query response and potentially the type of the NAS
query. In case of a NAS service provider query, the response may
comprise a PSP list. This PSP list may include unique PSP
identifiers, such as PSP full names, sometimes referred to as
PSP-IDs in the long format. The PSP identifiers may be of variable
length and the PSP list may include any number of PSP identifiers.
The NAS message carrying the NAS query response may be segmented by
the RLC in the MF-AP. The RLC in the MF-AP may be configured to
operate in acknowledged mode (RLC-AM) or unacknowledged mode
(RLC-UM). The transport of the NAS query response from the MF-AP to
the UE may reuse transport mechanisms established for the
transmission of AS related control information, such as RRC
messages in LTE. The NAS message carrying the NAS query response
may be transmitted using the first or the second specific bearer
and channel configuration. The second specific bearer and channel
configuration, similar to SRB 2 in LTE, may be preferred in the
case of long NAS query responses. The MF-AP may set up a respective
radio resource configuration and respective protocol entities for
transmission of the NAS query response. The MF-AP may in particular
configure radio resources for the transmission of uplink control
information, similar to the physical uplink control channel (PUCCH)
in LTE.
[0110] A UE executing the NAS query procedure in FIG. 8 is only
known to the MF-CN by its random UE-ID after step 860. After
receiving the NAS query response the UE may decide to access the MF
network, for example, if the NAS query response indicates the
availability of a suitable or preferred PSP in a MF cell. For
accessing the MF network the UE may transmit a message comprising a
NAS service request, as shown in step 870 in FIG. 8. The message in
step 870 may identify the selected PSP and may further include the
UE-ID under which the UE is registered at the selected PSP. With
transport mechanisms for control information such as the first and
the second specific bearer and channel configuration already being
established, the message of step 870 may cause a reconfiguration of
the connection between the UE and the MF-CN. Specifically, the
message may cause establishment of a transport mechanism for user
data between the UE and the MF-CN, similar to the EPS bearer in
LTE. Accordingly, the message may cause configuration of respective
interfaces for user data transmission, similar to the S1 u-plane in
LTE. The message may further cause authentication of the UE and the
MF-CN to each other. In an embodiment the UE may use in step 870 a
message similar to the RRCConnectionReconfiguration message, but
with cause information "NAS service request" and the selected
PSP.
[0111] In step 875 the MF-AP may provide information related to the
NAS service request in the NAS message of step 870 to the MF-CN.
This NAS message may cause the MF-CN to perform all steps needed on
the side of the MF-CN for user data transmission between the UE and
the MF-CN, such as establishing a respective transport mechanism
and related interfaces, and authentication.
[0112] The MF-CN may confirm the NAS service request from the UE in
the NAS message in step 880. The message may include information
for attachment of the UE to the MF-CN, for example information
related to the established transport mechanism for user data
transmission.
[0113] In step 885 the MF-AP may provide information needed for
attachment of the UE received in step 880 to the UE.
[0114] In step 890 the UE may confirm attachment of the UE to the
MF network for service access to the PSP. The message may comprise
reconfiguration information related to the transport mechanism for
user data transmission between the UE and the PSP.
[0115] In case the UE decides after reception of the NAS query
response in step 860 not to access the MF network, the UE may
trigger a connection release operation by sending a respective
request to the MF network. The MF network may then remove all UE
context information related to the random UE-ID from the MF
network. In an embodiment the connection release procedure may
comprise the transmission of connection release message to the UE,
similar to the RRCConnectionRelease message in LTE.
[0116] Such an explicit release signaling and the related handshake
mechanism require time, radio and network resources for maintaining
the UE in a MF cell even though the UE has decided not to use the
MF cell for access to the MF network. Further, the connection
release procedure using explicit signaling may not always work
reliably, and the UE may, from the perspective of the MF-AP and the
MF-CN, simply disappear after the transmission of the NAS query
response. Therefore, the MF-AP and/or the MF-CN may maintain a
timer. This timer may for example be started after delivery of the
NAS query response. Upon expiry of the timer, the MF network may
start a connection release procedure, and the MF network may remove
all UE context information related to the random UE-ID from the MF
network. The MF-AP may inform the UE about the connection release
procedure. In case the connection release procedure is executed for
a UE after transmission of the NAS query response, even though the
UE intended to attach to the MF network via the selected MF cell,
the UE can still send a connection request including the selected
PSP, its registered UE-ID and a NAS service request after
performing a RACH procedure but without repeating the NAS query
procedure, since the PSP list is already available in the UE.
[0117] The invention can be implemented to a UE as a set of radio
features and signaling procedures. The invention can be implemented
as a network architecture elements and protocols executed therein.
The UE can refer to any 3GPP device category including smart
phones, laptops, wearables, machines and internet of things.
[0118] The invention has several advantages. It defines a 3GPP
compatible standalone network, which can operate on the unlicensed
frequency band satisfying the unlicensed spectrum access
requirements such as bandwidth occupancy, power levels and
listen-before-talk mechanisms.
[0119] The invention allows a UE accessing any local dimension
network having e.g. Ethernet connectivity, to connect to a cellular
packet core network element that is reachable locally.
[0120] In comparison to LTE aggregated WLAN solutions, this
solution avoids the need of the eNB to configure the UE for a WLAN
access, connection establishment. The invention avoids the need of
UE to run different sets of protocols for its connectivity (i.e. UE
can just run 3GPP instead of 3GPP+WLAN systems). Further, this
allows simpler and more consistent control operation by the RRC
Connection Reconfiguration compared to separately controlling 3GPP
connection and WLAN connection.
[0121] In MF network, the UE is in LTE states both in the radio
level (idle state and RRC Connected state/LTE connected state) and
towards the core network UE is in the attached state (or detached
state). Hence, having the MF network protocols, there is no need to
introduce any change at radio level (specification and
implementation). These issues are not faced in WLAN, neither these
benefits can be reached in WLAN.
[0122] The invention with query has additional benefits, such as
avoiding broadcasting long System Information messages with full
service provider identity (e.g. FQDN), avoiding selection of access
points which do not offer the preferred service or preferred
service provider selection, avoiding selection of a network, which
is not capable of serving with sufficient performance and quality,
avoiding unnecessary switching from the idle state to the LTE
connected state, and avoiding setting up the eps-bearer, interfaces
and ATTACH, unnecessarily.
[0123] It is to be noted that embodiments of the present invention
may be implemented as circuitry, in software, hardware, application
logic or a combination of software, hardware and application logic.
In an example embodiment, the application logic, software or an
instruction set is maintained on any one of various conventional
computer-readable media. In the context of this document, a
"computer-readable medium" may be any media or means that can
contain, store, communicate, propagate or transport the
instructions for use by or in connection with an instruction
execution system, apparatus, or device, such as a computer or smart
phone, or user equipment.
[0124] As used in this application, the term "circuitry" refers to
all of the following: (a) hardware-only circuit implementations
(such as implementations in only analog and/or digital circuitry)
and (b) to combinations of circuits and software (and/or firmware),
such as (as applicable): (i) to a combination of processor(s) or
(ii) to portions of processor(s)/software (including digital signal
processor(s)), software, and memory(ies) that work together to
cause an apparatus, such as a mobile phone or server, to perform
various functions) and (c) to circuits, such as a microprocessor(s)
or a portion of a microprocessor(s), that require software or
firmware for operation, even if the software or firmware is not
physically present. This definition of `circuitry` applies to all
uses of this term in this application, including in any claims. As
a further example, as used in this application, the term
"circuitry" would also cover an implementation of merely a
processor (or multiple processors) or portion of a processor and
its (or their) accompanying software and/or firmware. The term
"circuitry" would also cover, for example and if applicable to the
particular claim element, a baseband integrated circuit or
applications processor integrated circuit for a mobile phone or a
similar integrated circuit in server, a cellular network device, or
other network device.
[0125] If desired, the different functions discussed herein may be
performed in a different order and/or concurrently with each other.
Furthermore, if desired, one or more of the above-described
functions may be optional or may be combined.
[0126] Although various aspects of the invention are set out in the
independent claims, other aspects of the invention comprise other
combinations of features from the described embodiments and/or the
dependent claims with the features of the independent claims, and
not solely the combinations explicitly set out in the claims.
[0127] It should also be understood that the above described
example embodiments of the invention are not to be viewed in a
limiting sense. Rather, there are several variations and
modifications which may be made without departing from the scope of
the present invention as defined in the appended claims.
[0128] The following meanings for the abbreviations used in this
specification apply: [0129] 3GPP The 3rd Generation Partnership
Project [0130] ANQP Access Network Query protocol [0131] CQI
Channel Quality Indicator [0132] EPC Evolved Packet Core Network,
or a network element [0133] EPS Evolved Packet System, in here
including EPS, and/or MF EPS [0134] FQDN Fully Qualified Domain
Name [0135] IP Internet Protocol [0136] LAA Licensed Assisted
Access of LTE [0137] LBT Listen-Before-Talk mechanism to access
unlicensed spectrum by LTE [0138] LTE-U LTE operating in unlicensed
frequency band [0139] MME Management entity of the MF CN, or a
Mobility Management Entity of the EPC [0140] MF MuLTEfire; a local
area scoped network with NAS access procedures [0141] MF-AP Access
point of a MF network [0142] MF CN MF core network element [0143]
NAS Non-Access Stratum [0144] PDCP Packet Data Convergence Protocol
[0145] PRB Physical Resource Block [0146] QCI QoS Class Identifier
[0147] RRC Radio Resource Control [0148] SDU Service Data Unit
[0149] TCP Transmission Control Protocol [0150] UDP User Datagram
Protocol [0151] UE User Equipment
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